Hammond 125B (1590N1) enclosure dimensions

Wall thickness, casting taper and a free drill template

External, at the rim
65.5 × 121.2 × 35.8mm

2.58 × 4.77 × 1.41 in

Drilled face
63.6 × 119.3mm

the face you lay out

Usable flat area
52.1 × 107.8mm

inside the walls and bosses

Wall thickness
1.8mm

1 mm draft per side

Lay out a 125B →

Free in your browser, and it prints a true-size drill template.

The 125B (Hammond's own part number for it is 1590N1) is the most popular enclosure in DIY pedal building. It is a little wider, taller and usefully deeper than a 1590B, which is exactly the margin a through-hole build with board-mounted pots needs, and it is the size most PedalPCB and Aion FX boards are designed around.

If you are building from a mainstream PCB and the vendor does not say otherwise, this is almost always the enclosure they mean.

125B drawing

AABB SECTION A-ASECTION B-B 63.6119.3R4.5R4 BOSS35.865.5 AT RIM(R1.3) EDGE1.8 WALL1 DRAFT(35.8) NOTES1.MATERIAL: DIE-CAST ALUMINIUM ALLOY2.INTERNAL CAVITY 60.1 x 115.8 AT THEDRILLED FACE3.USABLE FLAT AREA 52.1 x 107.8 INSIDETHE CORNER BOSSES4.LID FIXING: 4 OFF 6-32 UNC5.HIDDEN LINES ARE THE INSIDE FACE OFTHE WALL AND THE CORNER BOSS KEEPOUT6.CASTING DRAFT DRAWN AT TRUE SCALE7.TOP EDGE ROLLOVER R1.3 NOMINAL, NOTA MEASURED FIGURE HAMMOND 125BDIMENSIONS IN MMSCALE: TO FITSOURCE: HAMMOND CADSTOMPBOXLAYOUT.COMTHIRD ANGLE
The drilled face, with the inside of the wall and the corner screw bosses as dashed hidden lines, and two sections cut on the centrelines showing the wall, the casting draft and the rolled top edge. Drawn from the CAD, so it agrees with the figures below it. Drag the drawing sideways to see the rest of the sheet.

Full specification

External footprint (at the open rim) 65.5 × 121.2 mm (2.58 × 4.77 in)
Drilled (top) face 63.6 × 119.3 mm (2.50 × 4.70 in)
Depth 35.8 mm (1.41 in)
Wall thickness 1.8 mm
Wall taper (per side, face to rim) 1 mm
Corner radius 4.5 mm
Screw boss reach (each corner) 4 mm
Internal cavity (at the face) 60.1 × 115.8 mm (2.37 × 4.56 in)
Usable flat area (inside the bosses) 52.1 × 107.8 mm (2.05 × 4.24 in)
Material Die-cast aluminium alloy
Lid screws 4 × 6-32 UNC

Figures are derived from Hammond's own STEP models and datasheets, the same data the editor and the comparison tool use. Official drawing, 3D CAD and specification sheet: Hammond's 1590N1 part page.

How thick are the walls?

The 125B's walls are 1.8 mm thick. Like every diecast enclosure it also carries a casting draft: each wall leans out by 1 mm from the drilled face to the open rim, so the enclosure measures 65.5 × 121.2 mm at the rim and 63.6 × 119.3 mm across the face you drill. Worth knowing when a part seats against the inside of a wall, and why a caliper reading depends on where you take it.

What fits inside?

The internal cavity measures 60.1 × 115.8 mm at the face, and the screw bosses in each corner reduce the usable flat area for a circuit board to about 52.1 × 107.8 mm. To check a specific board, put its dimensions into the enclosure comparison tool's fit checker, or place the whole layout in the editor, which knows each component's real footprint and warns when something clashes with a wall or a boss.

125B drill template

The Stompbox Layout editor has the 125B as a built-in preset. Place your holes on it, and it prints a true-size PDF drill template with the enclosure outline, every hole position and a ruler to verify your printer's scale. Free, no download, runs in the browser.

Printed at 100% scale it works as a drilling template: tape it to the enclosure, centre punch each mark, then drill. Our guide to hand drilling a pedal enclosure walks the whole job, bit sizes included.

Or start from a ready-made layout: browse the 125B drill templates built for popular PCB vendors' boards.

A 3D printed drill jig sitting over a pedal enclosure.

3D printable drill jigs for the 125B

Building a PedalPCB or Aion FX board? A ready-made jig pack covers this enclosure: nothing to tape down, nothing to slip, and it wraps the sides so the jacks line up.

PedalPCB pack, $12 → Aion FX pack, $12 →

How the 125B compares

Enclosure External at the rim Drilled face Depth Usable flat area
125B (Hammond) 65.5 × 121.2 mm 63.6 × 119.3 mm 35.8 mm 52.1 × 107.8 mm
1590B 60.5 × 112.4 mm 59.3 × 111.2 mm 27 mm 47.3 × 99.2 mm
1590BB 119.5 × 94 mm 116.9 × 91.4 mm 30 mm 104.4 × 78.9 mm
125B (Tayda) 67 × 122.1 mm 64.7 × 119.8 mm 35.3 mm 52.3 × 107.4 mm

125B vs 1590B

The 1590B is 4.3 mm narrower, 8.1 mm shorter and 8.8 mm shallower than the 125B. The 125B is the safer default; the 1590B is the choice when compactness beats convenience.

125B vs 1590BB

The 1590BB is 53.3 mm wider, 27.9 mm shorter and 5.8 mm shallower than the 125B. Move up to the 1590BB when the build needs two footswitches or more knobs than a single column of four.

Hammond vs the Tayda 125B

Tayda's 125B-style enclosure is its own casting, not a relabelled Hammond, and we measure both. Across the drilled face it runs +1.1 mm in width and +0.5 mm in height against the Hammond, with 2.2 mm walls (Hammond: 1.8 mm) and 35.3 mm of depth (Hammond: 35.8 mm). A drill layout made for one fits the other for ordinary builds; re-check tight clearances near the walls and corners. Both castings are in the comparison tool if you want them drawn to scale.

125B FAQ

What are the dimensions of a 125B enclosure?

A Hammond 125B measures 65.5 × 121.2 mm × 35.8 mm externally at the open rim (2.58 × 4.77 in). The drilled face measures 63.6 × 119.3 mm, and the usable flat area inside the walls and corner screw bosses is about 52.1 × 107.8 mm.

How thick are the walls of a 125B?

The 125B's walls are 1.8 mm thick, with a casting draft of 1 mm per side from the drilled face to the open rim.

Is there a drill template for the 125B?

Yes. The free Stompbox Layout editor includes the 125B as a preset and prints a true-size PDF drill template of your layout, with a ruler to verify print scale.

Is the 125B the same as the 1590N1?

Yes. 1590N1 is Hammond's own part number and 125B is the name the pedal-building world uses, from the older Bud/Eddystone enclosure of that size. They are one enclosure: 65.5 × 121.2 mm × 35.8 mm at the rim, and every figure on this page applies to both.

Every enclosure size

1590LB

49.3 × 49.3 mm face, 27 mm deep

Dimensions →

1590A

37.1 × 91.2 mm face, 27 mm deep

Dimensions →

1590B

59.3 × 111.2 mm face, 27 mm deep

Dimensions →

1590BS

58.6 × 110.1 mm face, 38 mm deep

Dimensions →

1590BB

116.9 × 91.4 mm face, 30 mm deep

Dimensions →

1590BB2

118.1 × 92.6 mm face, 33.8 mm deep

Dimensions →

1590BBS

117.8 × 92.3 mm face, 38.1 mm deep

Dimensions →

1590J

143.4 × 93.4 mm face, 45.1 mm deep

Dimensions →

1590XX

143.4 × 119.4 mm face, 35.2 mm deep

Dimensions →

1590P1

80.6 × 150.6 mm face, 46.4 mm deep

Dimensions →

1590DD

185.7 × 117.7 mm face, 33 mm deep

Dimensions →

Or see them drawn to scale, side by side.

Plan your 125B layout

Place the drill holes on a 125B in the editor, check everything clears the walls and the screw bosses, then print a true-size PDF drill template. Free, in your browser.

Start designing free →